Field
This relates to tools and other dynamic products and associated components and the machines that drive them, methods for making and using those products, tools, associated components and machines, including cutting and abrading elements, saw blades, grinders, coring bits and other tools for boring holes, tool guards, fluid and debris collectors, as well as fluid supply, control and distribution components for such tools and components, including nozzles, valves and other fluid flow components.
Related Art
Tools used for cutting, grinding, abrading or other working of work pieces are often made from metal or other relatively heavy materials for strength and longevity. One such material includes steel but others have been used or suggested as well. Heavier tools mean that additional horsepower is used to operate the tool, and for portable and handheld tools, additional weight means heavier equipment and more difficulty in handling.
Tools such as power or driven tools often develop heat and also debris during use. When the tool operates at higher temperatures, those temperatures can lead to a shorter lifetime for the tool, and therefore higher costs, for example relating to more frequent replacement. Tool operating temperatures can be reduced by using the tool at lower speeds and/or by cooling the tool, for example by spraying the tool with water.
Lower tool operating speeds often result in longer project times because the tool must be used longer at the lower speed to complete the project. Additionally, some tool operations still require cooling with a fluid even when the tool is operated at lower speeds. Fluid may also be used to clear away debris from the operating site.
Fluids used to cool tools or remove debris from an operating site have included water, oil, drilling mud, as well as other water-based and oil-based fluids. Many of these fluids are contained, for example in reservoirs or through vacuum recovery, so as to minimize contamination of surrounding areas, but often large amounts of fluid are used during the operation and may be difficult to reuse or recycle. As a result, large amounts of fluid may be consumed during operation of the tool.
While water is a common fluid for cooling and removing debris, water can be corrosive for tools that cannot be easily dried after use. For example, tools that are cooled with water and have multiple parts are sometimes difficult to dry or to eliminate corrosion, and water may enter and stay in areas between adjacent parts. The water can then lead to corrosion and possibly shorter lifetime for the tool.
One tool that is often cooled with water is a masonry or concrete saw blade. Many conventional concrete saw blades are cooled by spraying or otherwise applying water to the blade. The water may be sprayed onto the sides of the blade, but large amounts of water are used to reduce the blade temperature. As a result, the water along with any particles produced during cutting spread across the work area. In many situations, the water and debris must be removed before the area can be used. For example, the water and debris must be removed from airport runways and highways to minimize the possibility of the debris fouling the environment or equipment using the runways and highways. Relatively large vacuum systems are used to pick up the water and debris because of the large amount of water used during the cutting operation. Spraying large amounts of water on the fast-turning blade produces a significant amount of deflected water. In order to contain as much of the water as possible around the blade, blade guards used to protect users from injury are often designed to enclose the blade as much as possible. With such blade guards, the user finds it more difficult to see and monitor the blade and the cutting operation.
Spraying large amounts of water on the fast-turning blade also produces a large amount of pooling around the blade. As a result, a large portion of the cooling water remains on the work surface and does not make its way to the cutting area. Less water reaches the cutting area and it is more difficult to remove the debris without the additional water. The additional debris also tends to raise the blade temperature.
In other designs, water may be forced between plates or discs forming a core of the saw blade. Many conventional masonry or concrete saw blades also use hardened particles embedded in an outer rim, either in a continuous ring or cutting segments mounted about the perimeter of a steel core. The hardened particles may be diamond, tungsten carbide, poly-crystalline diamond, and the like. The steel core may be formed from one or more supporting discs. Where multiple discs are used to support the segments, any water that enters between the discs may cause corrosion and pre-mature blade failure. Consequently, most concrete saw blades are water cooled with spray on the outer sides of the discs.
The blade cutting segments on a segmented saw blade are typically arcuate segments about two inches long and silver soldered, brazed or welded about rim portions of the steel core. The core includes radially extending sections separated by grooves or gullets. The arcuate segments are mounted to the radially extending sections. The gullets help to accommodate stresses during cutting operations. Coolant used to cool the blade also helps to flush debris from the cutting area during the cutting operation, which reduces blade temperature. The coolant helps to remove loose sand, rock-like material, spent abrasive material and other granular material from the cutting location, called a “kerf”, and the debris is termed “swart”, and the fluid-containing-swart is called a slurry. As a result of the temperature and motion of the slurry around the junction of the steel core and the cutting segments, the junction material erodes and wears away, reducing the core support of the segments. The erosion, known as “under cutting”, shortens the blade lifetime. U.S. Pat. Nos. 4,718,398, 4,854,295 and 5,471,970, and published patent application U.S. 20030213483, to Sakarcan discuss cutting blades, the disclosures of which are incorporated herein by reference.